1. Field of the Invention
This invention relates to an apparatus for aligning first and second tool sections such as mold halves and tools utilizing same.
2. Background Art
Tool sections such as mold halves must become properly aligned during closing so that any parts or cavities on one tool section are accurately registered with corresponding parts or cavities on the other tool section in a closed position of the sections.
Molds generally have at least two halves which move together and apart during their routine cyclic operation. One of the mold halves usually includes at least four leader pins which fit into complementary bushings in the opposite mold half. When the mold closes, these pins and bushings align the two mold halves. An example of such a pin and bushing mounted in their respective mold halves is shown in FIG. 1.
U.S. Pat. No. 4,386,868 discloses a leader pin for guiding and directing the halves of a mold as it opens and closes. The pin has a base, a shoulder at one end of the base, and a frustoconical tapered section which extends outwardly from a ledge on the base. A cylindrical guide pin projects outwardly from the narrow end of the tapered section. The tapered section and the guide pin fit into a complementary tapered and cylindrical opening in the sleeve of a bushing. The two tapered sections guide, direct, and align the mold halves.
The following U.S. patents are also related to the present invention: U.S. Pat. Nos. 2,339,792; 3,776,299; 3,870,092; 3,970,138; and 4,199,313.
One problem associated with the prior art in general is that larger and, consequently, heavier tool sections need to be aligned. The bushings mounted on one of the tool sections often times cannot withstand the relatively large amounts of side forces or pressures (i.e., loads) from their respective pins which are mounted on the other of the tool sections.